A couple weeks ago, I was trying to decide if it was worthwhile to leave deleted files in the Google Desktop Search index. After all, if the file is gone, do I really care to know that I deleted that thing I am now looking for? Today, I got my answer. Since Desktop Search caches the text in its index, it can be quite useful to retrieve things that are no longer around. In my case, I was looking for an Outlook Note that I had inadvertently deleted some time ago, so long ago that it was not present in the deleted items folder either. Google still had the text in the index, so I was able to recreate what I had previously hosed. So, long story short, it is probably a good idea to leave the Remove Deleted Items option unchecked.